1. Field of Invention
This invention relates to the renewable energy technology, and more particularly to a composite catalyst for an electrode and to an electrochemical cell, such as a fuel cell or direct methanol fuel cell (DMFC), that includes an anode with the same thereon.
2. Description of Related Art
Among new energy technologies, fuel cell is particularly promising. The most promising type of fuel cell ought to be the direct methanol fuel cell (DMFC), for methanol is cheap, safe, easy to store and deliver as compared with hydrogen, and higher in the electrochemical activity as being an alcohol having the least carbon number. In a prior-art DMFC system, the anode catalyst material usually includes platinum (Pt). However, at low temperature, methanol is incompletely oxidized to produce CO on pure platinum electrode, where strong chemisorption of CO takes place on the active sites and poisons the catalyst. As a result, methanol oxidation as well as the electrochemical performance of the anode is significantly lowered.
For pure Pt anode for DMFC, the catalyst is easily poisoned due to incomplete oxidation of methanol, so that the development of pure Pt catalysts is limited. Hence, many researchers turned to study bimetallic catalysts like PtRu. However, PtRu catalysts suffer from problems like Ru dissolution during the electrochemical reaction.